Dear Gurus,
Two days ago I asked
   We are planning to build a TruCluster consisting of two AlphaServer, a
   raid array and memory channel interconnect, which will be necessary
   for the TruCluster software V5 comming soon.
   Someone told me that it will be usefull to use a memory channel hub
   even in a two node cluster, just to isolate hardware problems of the memory
   channel adapter.
   Is this statement true?
Thanks to 
"Randall R. Cable" <randy.cable_at_mci.com>
"Vipin Gokhale, Compaq SBU, Oracle Corporation" <VGOKHALE_at_us.oracle.com>
Ed Bush <edbush_at_llnl.gov>
Balaji Chandrasekar <digital_at_astro.ocis.temple.edu>
Stephen Carpenter <sac_at_uvo.dec.com>
Kai Grunau <kgrunau_at_ifm.uni-kiel.de>
All but one followed the statement to integrate a Memory Channel Hub
into the MC Interconnect even for a two system cluster for different 
reasons:
- "Without a hub the systems cannot determine which end has 
  the fault and this may result in BOTH nodes crashing." (Stephen Carpenter)
- much more easy to expand the cluster to more nodes / no hard- and software 
  reconfiguration of the two existing nodes (-> no virtual hub)
- better performance of the MCI (-> no virtual hub)
Nevertheless a cluster without hub will work quite well (most of the time).
Thanks again
Gerhard
-- 
Gerhard Nolte
Email: gnolte_at_gwdg.de   Voice: +49-551-5176-716  Fax: +49-551-5176-704
MPI fuer Stroemungsforschung, Bunsenstr. 10, 37073 Goettingen, Germany
Received on Fri Aug 21 1998 - 07:42:10 NZST